| Summary: | mention of ssh-keygen in ssh connect warning | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Jozef Mlich <jmlich83> |
| Component: | openssh | Assignee: | Jakub Jelen <jjelen> |
| Status: | CLOSED EOL | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 25 | CC: | jjelen, mattias.ellert, mgrepl, plautrba, tmraz |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2017-12-12 10:47:58 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
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Description
Jozef Mlich
2016-04-29 06:26:18 UTC
I can quote upstream maintainer Darren Tucker from the upstream bug [1]: > Sorry, but having the error message suggest something that is exactly the wrong thing to do in the case of an active MITM attack is not something we want to do. I share this opinion. We have no intention to diverge from upstream more than necessary. Especially not in this place which affects the only security check that is needed from the user to prevent MitM. Who knows what is doing will do that anyway and who does not know is advised to find out. Unfortunately, you are right and Ubuntu ships this patch [2]. But it does not mean that we have to ship everything Ubuntu does. Leaving open for constructive discussion or other insights, if there will be some, but I don't see any good reason for applying this patch. [1] https://bugzilla.mindrot.org/show_bug.cgi?id=1843 [2] http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/wily/openssh/wily/view/head:/debian/patches/mention-ssh-keygen-on-keychange.patch I agree with better formulation of the message with explicit information "This could be Man in the middle attack". However I think it's worth it to show the command to remove SSH key when required. I find it a better solution than to delete known_hosts file like many people do as it's working for them but they are unaware of the security risk. Some people even recommend to disable that check using: Host * StrictHostKeyChecking no UserKnownHostsFile=/dev/null But I think this solution is far worse for security than the solution recommended above. (In reply to Jozef Mlich from comment #2) > Some people even recommend to disable that check using: > > Host * > StrictHostKeyChecking no > UserKnownHostsFile=/dev/null > > But I think this solution is far worse for security than the solution > recommended above. Yes. It is worse, but it is not advised in the response to the possible MitM attack by the ssh tool itself so it is not a valid point to improve security. Wording > Offending key for IP in ... > remove with: ssh-keygen -f \"%s\" -R tells > there is a problem, resolve it by doing this. which is NOT what you should do in every situation. It is true that in most cases you DO that and the alarm is "false", but it is certainly not something you should do always without thinking. This bug appears to have been reported against 'rawhide' during the Fedora 25 development cycle. Changing version to '25'. openssh-7.2p2-11.fc24 selinux-policy-3.13.1-191.8.fc24 has been submitted as an update to Fedora 24. https://bodhi.fedoraproject.org/updates/FEDORA-2016-99191c4aab Reverting to NEW state. BZ was switched to MODIFIED due to wrong bodhi update. This message is a reminder that Fedora 25 is nearing its end of life. Approximately 4 (four) weeks from now Fedora will stop maintaining and issuing updates for Fedora 25. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '25'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 25 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. Fedora 25 changed to end-of-life (EOL) status on 2017-12-12. Fedora 25 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed. |